Overall Special Teams Performance

I remember hearing Ken and Mick talking a while back about coaches wanting powerplay percentage + penalty kill percentage to add up to (at least) one hundred percent. Beyond that, I don't often hear people talking about overall special teams performance in terms of PP + PK percentages. I was curious what the totals looked like and how they compared to overall team performance. This is what I came up with.

It's arranged from highest total to lowest total. I included the individual PP/PK percentages for reference, and the teams power ranking as well (which is calculated simply as points percentage).

Just a few observations: First, it jumps out that the first place team (Vancouver) is tops in the league and the last ranked team (Edmonton) is dead last overall. The two other teams that jumped out at me were Buffalo, who's ranked eleventh in overall special teams, but near the bottom in terms of points percentage. The other is Philly, who is second in the league points-wise but is right in the middle in terms of special teams.

Anyone notice anything else? Thoughts? Should this stat (overall special teams percentage) be calculated and referenced more, or is it fairly useless?